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Course Outline

Vessel operators may not hear sound signals or voices if the engine is not adequately muffled.

  • A vessel’s engine must have a factory-installed muffler or exhaust system for noise reduction, or another effective muffling system.
  • Michigan law states that a vessel’s muffler or exhaust system must prevent noise in excess of:
    • 90 decibels at idle from three feet away and...
    • 75 decibels when measured from the shore.
  • Unit 4 of 6
  • Topic 8 of 19
  • Page 4 of 4